History of Anatomy

As you bend with the rigid blade of your scalpel over the unknown corpse, remember that this body was born of the love of two souls, it grew rocked by faith and for the hope of the one who sheltered him in her bosom. He smiled and dreamed the same dreams as children and young people. Certainly he loved and was loved, he hoped and cherished a happy tomorrow, and he missed the others who had departed. Now it lies on the cold slate, without a single tear having been shed for it, without a single prayer. His name, only God knows. But inexorable fate gave him the power and greatness to serve humanity. The humanity that passed him indifferently

(Rokitansky, 1876)

Anatomical knowledge of the human body dates back to five hundred years before Christ in southern Italy with Alcméon of Crotona, who performed dissections in animals. Shortly thereafter, a clinical text from the Hippocratic school discovered the anatomy of the shoulder as it had been studied with dissection. Aristotle mentioned anatomical illustrations when he referred to paradigms, which were likely figures based on animal dissection. In the third century BC, the study of anatomy advanced considerably in Alexandria. Many discoveries made there can be attributed to Herophilus and Erasistratus, the first who systematically performed human dissections. From the year 150 BC human dissection was again prohibited for ethical and religious reasons. Anatomical knowledge about the human body continued in the Hellenistic world, but it was only known through animal dissections. In the second century AD, Galen dissected almost everything, monkeys and pigs, then applying the results obtained to human anatomy, almost always correctly; however, some errors were unavoidable due to the impossibility of confirming the findings in human cadavers. Galen nevertheless developed the doctrine of the "final cause", a theological system that required all findings to confirm physiology as he understood it.

However, anatomical illustrations from the classical period have not yet come down to us, as the medieval “five-figure series” of bones, veins, arteries, internal organs and nerves are probably copies of drawings above. Invariably, the figures are represented in an open frog-like position, to demonstrate the different systems, sometimes a sixth figure is added representing a pregnant woman and male or female sexual organs. In ancient bas-reliefs, cameos and bronzes often appear representations of skeletons and shrunken bodies covered with skin (called lemurs), of a magical or symbolic character rather than schematic and without any didactic purpose.

It seems that the study of human anatomy has started again for practical reasons rather than intellectual ones. War was not a local affair and it became necessary to have the means to repatriate the bodies of those killed in combat. Embalming was sufficient for short journeys, but longer distances such as the Crusades introduced the practice of “boiling the bones”. Boniface VIII's papal bull De sepulturis (1300), which some historians mistakenly believed prohibited human dissection, attempted to abolish this practice. The most important reason for human dissection was the desire to know the cause of death for essentially medico-legal reasons, to find out what had killed an important person or to elucidate the nature of the plague or other infectious disease.

The verb “dissect” was also used to describe the increasingly frequent cesarean operation. The manuscript tradition of the medieval period was not based on the natural world. Previous illustrations were accepted and copied. In general, the writers' abilities were limited, and in examining natural reality they introduced at least some errors, both in concept and technique. Things were "seen" just like the ancients, and realistic illustrations were considered to short-circuit the method of study itself.

Anatomy was not an independent discipline, but an auxiliary to surgery, which at that time was relatively crude and brought together, above all, knowledge of the appropriate points for bleeding. For as long as anatomy has held this opposite quality to practice, unrealistic, schematic figures have sufficed.

The first illustrated book with printed rather than painted images was the work of Ulrich Boner Der Edelstein. It was published by Albrecht Plister in Banberg after 1460 and its illustrations were something more than vulgar decorations. In 1475 Konrad Megenberg published his Buch der Natur, which included several wood engravings depicting fish, birds, and other animals, as well as various plants. These figures, like many others from books on nature and encyclopedias from this period, are within the manuscript tradition and are hardly identifiable.

Among the many factors that contributed to the development of the illustrative technique in the beginning of the 16th century, two occupied a prominent place: the first was the end of the manuscript tradition consisting in copying ancient drawings and the conversion of nature into the primary model. It came to the conviction that what was most suitable for man was the natural world and not posterity. The scholasticism of St. Thomas Aquinas had inadvertently prepared the way through the separation between the natural and the supernatural world, with theology prevailing over natural science. The second factor that influenced the development of scientific illustration for teaching was the slow introduction of better techniques. In the beginning, the editors, with a purely quantitative criterion, thought that with the press they could make a large number of reproductions easily and cheaply. Only later did they recognize the importance of each illustration being identical to the original. The ability to accurately repeat pictorial reproductions of what was observed was the distinguishing feature of several scientific disciplines, which discarded their earlier support for tradition and acceptance of a methodology that was descriptive at first and experimental later.

The first printed anatomical illustrations are based on the medieval manuscript tradition. The Fasciculus Medicinae was a collection of texts by contemporary authors aimed at practical physicians, which reached many editions. In the first (1491) woodcutting was used for the first time for anatomical figures. The illustrations represent human bodies showing the bleeding points, and lines connecting the figure to the explanations printed in the margins. The dissections were designed in a primitive and unrealistic way.

In the Second Edition (1493), the positions of the figures are more natural. Hieronymous Brunschwig's texts (circa 1450-1512) continued to use descriptive illustrations. The final chapter of a work by Johannes Peyligk (1474-1522) consists of a brief anatomy of the human body as a whole, but the eleven wood engravings it includes are more than later schematic representations of the Arabs. In George Reisch's Margarita philosophica (1467-1525), which is an encyclopedia of all the sciences, some innovations in traditional wood engraving are placed and the abdominal viscera are realistically represented.

In addition to these anatomical texts specifically intended for medical students and physicians, many other pages were printed with anatomical figures, entitled not in Latin (like all works for physicians), but yes in several common languages. There was great interest, for example, in the conception and formation of the human fetus. The frequent use of the phrase “know thyself” speaks of a philosophical and essentially non-medical orientation. The “Dance of Death” became a very popular theme, especially in German-speaking countries, after the Black Death and surprisingly, the representations of skeletons and the human anatomy of the artists who designed them are better than those of the anatomists.

The Renaissance artists of the 15th century were increasingly interested in human forms, and the study of anatomy was a necessary part of the training of young artists, especially in northern Italy.

Leonardo da Vinci (1452-1519) was the first artist to consider anatomy beyond a merely pictorial point of view. He made preparations which he soon drew, of which more than 750 are preserved, and represent the skeleton, muscles, nerves and vessels. Illustrations were often completed with annotations of the physiological type. Leonardo's precision is greater than Vesalio's and his artistic beauty remains unchanged. His correct appreciation of spinal curvature has been forgotten for over a hundred years. He correctly represented the position of the fetus in utero and was the first to point out some known anatomical structures. Only a few contemporaries saw his tracts, which undoubtedly were not published until the end of the last century.

Michelangelo Buonarotti (1475-1564) spent at least twenty years acquiring anatomical knowledge through the dissections he personally practiced, especially at the Santo Espírito convent in Florence. He later exposed the evolution to which he was subject, when he considered anatomy of little use for the artist until he thought that it contained an interest in itself, albeit always subordinate to art.

Albrecht Dürer (1471-1528) wrote works on mathematics, distillation, hydraulics, and anatomy. His treatise on the proportions of the human body was published after his death. His preoccupation with human anatomy was entirely aesthetic, ultimately deriving an interest in the classical canons, through which beauty could be acquired.

With the important exception of Leonardo, whose drawings were not within the reach of 17th century anatomists, the Renaissance artist was only a secondary anatomist. Important contributions were still made to the realistic representation of the human form (such as the use of perspective and shading to suggest depth and three-dimensionality), and true scientific advances required the collaboration of professional anatomists and artists. When anatomists were able to realistically represent correct anatomical knowledge, a period of intense investigation began throughout Europe, particularly in northern Italy and southern Germany. The best representative of this group is Jacob Berengario da Capri (+1530), author of Commentaria super anatomica mundini (1521), which contains the first anatomical illustrations taken from nature. In 1536 Cratander published in Basel an edition of Galen's works, which included figures, especially of osteology, done in a very realistic way. From as early as 1532, Charles Estienne prepared in Paris a work in which he emphasized the complete pictorial representation of the human body.

VESÁLIO

One ​​of the first and most accurate solutions for a perfect reproduction of graphic representations was found in the illustrations published in Andrés Vesálio's anatomical treatises (1514-1564), which culminated in his De humanis corpori, manufactured in 1553, one of the most important books in the history of man. Vesalius also proved that they are not the same in all individuals. He reported his surprise at finding numerous errors in Galen's works, and we have to emphasize the importance of his refusal to accept something just because he found it in the writings of the great Greek physician. Undoubtedly, despite having denied the existence of the orifices that Galen claimed to exist communicating the cardiac cavities, he was in every way a follower of Galenic physiology. The differences that separated his anatomical knowledge from that of Galen were magnified, starting with Vesalius himself.

Perhaps he thought that a controversy was a way of attracting attention. He then had a fierce dispute with his master Jacques du Bois (or Sylvius, in the Latin form), who was a convinced Galenist whose only answer, given the differences between some structures as seen by Vesalius and as Galen had described them, was that humanity must have changed it during these two centuries.

Vesálio had attributed the layout of the first figures to a certain Fleming, but at Fabrica he trusted no one, and the identity of the artist or artists who collaborated in his work has been the object of great controversy, which was accentuated by the question of who is more important, the artist or the anatomist. The latter was an irrelevant discussion, as it is obvious that illustrations are important precisely because they bring together a combination of art and science, a collaboration between artist and anatomist. Fabrica's figures imply so much anatomical knowledge that Vesalius was necessarily involved in the preparation of the drawings, although the degree of refinement and knowledge of new drawing techniques, also for Renaissance artists, also excludes that he was solely responsible. To this day, it is debated whether Jan Stephan van Calcar (1499-1456/50), who made the first figures and worked in Titian's studio in neighboring Venice, was the artist. Anyway, a solution had been found in the search for a pictorial expression adequate to natural phenomena.

In the 17th century, remarkable discoveries were made in the field of human anatomy and physiology. Francis Glisson (1597-1677) described in detail the liver, stomach and intestine. Although his views on biology were basically Aristotelian, he also had modern views, such as the one concerning the nerve impulses responsible for emptying the gallbladder.

Thomas Wharton (1614-1673) took a big step in overcoming the old and common idea that the brain was a gland that secreted mucus (no doubt, he continued to believe that tears originated there). Wharton described the differential features of the digestive, lymphatic, and sex glands. The evacuation conduit of the submandibular salivary gland is known as Wharton's conduit. An important contribution was to distinguish between internally secreting glands (now called endocrine), whose product falls into the blood, and externally secreting (exocrine) glands, which discharge into cavities.

Niels Steenson, in 1611, established the difference between this type of gland and lymph nodes (which received the name of gland despite not being part of the system). He thought the tears came from the brain. The new conception of the organism's transport systems, which was obtained thanks to the contributions of many researchers, helped to resolve the errors in galenic physiology related to blood production.

Gasparo Aselli (1581-1626) discovered that after an abundant ingestion of food, the peritoneum and intestine of a dog were covered with white fibers that, when sectioned, leaked a whitish liquid. These were the kiliferous capillaries. Until Harvey's time, breathing was thought to stimulate the heart to produce vital spirits in the right ventricle. Harvey, however, demonstrated that the blood in the lungs changed from venous to arterial, but he did not know the basis for this transformation. The explanation of the respiratory function took many years, but during the 17th century important steps were taken towards its clarification.

Robert Hook (1635-1703) demonstrated that an animal could also survive without lung movement if we inflated air into the lungs.

Richard Lower (1631-1691) was the first to perform direct blood transfusion, demonstrating the color difference between arterial and venous blood, which was due to the observation with the air from the lungs.

John Mayow (1640-1679) stated that the redness of venous blood was due to the extraction of some substance from the air. He came to the conclusion that the breathing process was nothing more than an exchange of air and blood gases; this gave away the nitro-air spirit and gained the vapors produced by the blood.

In 1664 Thomas Willis (1621-1675) published De Anatomi Cerebri (illustrated by Christopher Wren and Richard Lower), arguably the most detailed textbook on the nervous system. His anatomical studies linked his name to the circle of arteries at the base of the brain, the eleventh cranial pair, and also to a certain type of deafness. However, his obsession with locating mental processes at the anatomical level led him to reach equivocal conclusions; among them, that the brain controlled the movements of the heart, lungs, stomach and intestines and that the corpus callosum was a matter of imagination.

From then on, the development of anatomy accelerated. Berengario da Carpi studied the appendix and thymus, and Bartolomeu Eustáquio studied the ear canals. The new anatomy of the Renaissance required the revision of science. The Englishman William Harvey, educated in Padua, combined the Italian anatomical tradition with the experimental science that was born in England. His book on the subject, published in 1628, deals with anatomy and physiology. Alongside dissection problems and the description of isolated organs, he studies the mechanics of blood circulation, comparing the human body to a hydraulic machine. The improvement of the microscope (by Leeuwenhoek) helped Marcello Malpighi to prove Harvey's theory of blood circulation and also to discover the most intimate structure of many organs. Thus, the microscopic study of anatomy was introduced. Gabriele Aselli highlighted the lymphatic vessels; Bernardino Genga spoke, then, of “surgical anatomy”.

In the 18th and 19th centuries, the increasingly detailed study of operative techniques led to the subdivision of anatomy, giving great importance to topographic anatomy. The anatomical-clinical study of the cadaver, as a safer means of studying the alterations caused by the disease, was introduced by Giovan Battista Morgani. Pathological anatomy emerged, which allowed for great discoveries in the field of cell pathology, by Rudolf Virchow, and agents responsible for infectious diseases, by Pasteur and Koch.

Recently, anatomy has become submicroscopic. Physiology, biochemistry, electron and positronic microscopy, X-ray diffraction techniques, applied to the study of cells, are describing their intimate structures at the molecular level.

Currently, it is possible to study anatomy, even in living people, through imaging techniques such as radiography, endoscopy, angiography, computed axial tomography and tomography by positron emission, nuclear magnetic resonance imaging, echography, thermography and others.